All of my road rides eventually include some unpaved sections. It's always nice to get away from the cars and explore.
My 'road' bike is also my main 'gravel' bike. It's a steel road frame (56-square, 73/73) with clearance for 57mm calipers. Wheels are (currently) 25mm-wide HED with 28mm Panaracer Gravelking tires. Previously I ran Campy, microSHIFT, and Shimano in 9- and 10-speed, but am converting it to 11-speed SRAM (Force 22). It handles unpaved roads and trails quite well, and is a blast on paved roads.